Microsoft released the UI Guide and Design Templates for Windows Phone 7 some time ago. The design templates contained several Photoshop files showcasing common user interface elements of Windows Phone.

If you come from the world of always-use-stored-procedures or at least you always write your own SQL query, you’d be curious how LINQ to SQL translates your C# code to SQL query. Say you have table Persons with fields PersonId, FirstName, LastName, and Age. PersonId is the primary key of the table Persons.

In this example, we want to update a particular row (PersonId = 1) with a new Age value. So, we write the following block of code in our application.

If you’re used to writing your own query, you probably wonder why the WHERE clause is verbose (or wordy, an English major will say). You see the query tries to find the row to update by matching every single field in the table with their old values. “Well, that’s dumb, ain’t it?” you say. “We can find the row to update by matching only the value of the primary key, PersonId.” Here’s how.